The assay / refining lab.....second time around

[goldnugget77]

Hi 4metals!
You always come to the rescue
Thanks for taking the time to reply.

 

[4metals]

OK nugget here's the spreadsheet in Excel 2003

A few things, first the sheet is protected so you can only input data into the yellow colored cells AND you can change the correction factor. I put a correction factor of .999 in the sheet but a good assayer runs a correction with every furnace load. That being said, you can run a proof and put your own correction factor in. If you need to know how to run proofs let me know and I'll post the technique.

The sheet is also locked so you can't accidentally erase or delete the formulas but it is not password protected so you can unlock it and edit it if you like.

 

[goldnugget77]

Hi 4metals
Thanks very much for that program
I tried it out according to the samples I prepared before and I couldn't do it
Here is how it looks

 

[goldnugget77]

http://img30.imageshack.us/i/20289796.jpg/

 

[4metals]

Decimal point , decimal points, decimal points. When you put 2 decimal points in one number it is no longer a mathematical expression. All starting weights should have decimals too unless they are exactly a whole number.

 

[goldnugget77]

Hi 4metals
Thanks for taking the time to help

http://img34.imageshack.us/i/69780630.jpg/
Here I tried one more time
Using an imaginary batch
Did I enter all the yellow fields in the right way
Also is the result of the assay
14.86K for gold
and silver is
40.5%
is this correct
Thanks again

 

[4metals]

Gold sample weigh is the weight before you add silver. In your original question it was 0.5, which would make it 60% before correction. Plus the dore will always lose weight unless it is all precious metals with no base metals when you started.
Using the numbers you started with the answer is 14.86 PERCENT not Karat all answers in %

 

[goldnugget77]

Hi 4metals
I have tried it again I think this time its done right
Gold content is
59.44 %
Silver content is
20.5 %
Thanks

http://img75.imageshack.us/i/97292160.jpg/

 

[PreciousMexpert]

http://img75.imageshack.us/i/97292160.jpg/
I look at this picture
shouldnt the coronet wt Dore
for Ag cupel Number3
be 0.5
I dont know how he got 0.4
Thanks

 

[Irons]

I have the first 4 books, hardbound. I prefer the Shepherd and Dietrich and the Bugbee. I think both have been reprinted and are available at a fair price.

The last one is available here in pdf:
http://books.google.com/books?id=i_JMAAAAMAAJ&pg=PA237&lpg=PA237&dq=assaying+smith&source=bl&ots=fIso7h1poh&sig=5Vy2J417guUumYLtvvTK1bYx0WE&hl=en&ei=gxz-Sfu1II3NlQewiJGWCw&sa=X&oi=book_result&ct=result&resnum=7#PPP1,M1

I also have about 20 other old assay books, in pdf, that I downloaded from Google books.

Here's a good list to add:

http://tinyurl.com/ykwbuw7

 

[Refiner232121]

shouldnt the coronet wt Dore
for Ag cupel Number3
be 0.5
I dont know how he got 0.4

To me it does not make sense to have coronet wt Dore to be 0.4
I think it should be 0.5
because you are not going to be doing anything to that

 

[4metals]

The silver dore weight is .4 there is no silver added to this cupel because you are looking to find the silver content by difference. So you subtract the weight of the gold determined in the 2 cups parted to get the weight of the silver because the .4 is made up of the gold plus the silver in the original sample, and divide that by the start weight to get the silver percentage.

 

[PreciousMexpert]

Hi 4metals
The starting sample weight is 0.5
shouldnt the amount
for
coronet wt Dore
be also
0.5

 

[PreciousMexpert]

if you need a silver assay prepare a foil boat
the same as above but do not add silver.

Hi 4metals
Now I think i see why it should be 0.4
Thanks

 

[golddie]

I want to do a small test
In a small beacker
refine the gold
the way 4metals explains it
to get like coffe grounds using nitric and water


I direct the fumes
with a glass cover so that the fumes are absorbed by the water

Now I have Au,Ag,Cu,HNO3,H20

What would be the best way to process this waste

 

[golddie]

I found the solution
dealing with waste by 4metals

He says hang a slba of copper in the spent acid and all the metal will fall.
In that there will be gold ,silver ,copper
would it make sense to put all that in Aqua Regia
and process it from there

 

[golddie]

I would like to try to process this solution but I dont know where to start.
Remember I do not have the set up or any equipment

Au,Ag,Cu,HNO3,H20

I am thinking of adding some HCL
Now I have AR
The gold is dissloved.
Before getting rid of the nitric should I have done anything to drop the silver

 

[golddie]

This is what I am going to do
I got this from Hokes book
add hcl
now I have silver mud
seperate liquid from mud
denoxx
SO2
collect gold
I am left with copper nitrate

Did I do everything right
THanks

 

[Anonymous]

I'm looking for a machine that can make bone ash cupel
I hope someone can help me

4metals,

The assay setup (cupellation only) you've outlined will only work for high grade gold such as karat gold, dental gold, or gold bullion. Since about 80 - 90% of the 10,000 plus fire assays I've done have been on electronic materials, I think that should be discussed also. Besides all the equipment, etc., that you've mentioned, you will also need:

Assay crucibles. For general work, I prefer the 30 gram size.
Cone mold - available in 2, 3, or 6 depressions.
Crucible tongs

Litharge (lead oxide). I prefer the yellow rather than the red.
Borax - anhydrous or borax glass
Soda ash
Sugar or flour. I prefer sugar.
Silica sand.
Other occasionally used chemicals such as fluorspar and yellow sulfur.

The furnace should be heavy duty with thick insulation. Otherwise, the temperature will drop severely when putting the cold crucibles into the furnace. I prefer Cress furnaces with good temperature controllers.

 

[Oz]

I'm looking for a machine that can make bone ash cupel
I hope someone can help me

Miracle,
Please post a question only once. You have posted the exact same comment in three places within 5 minutes, please delete the other 2. Many read the entire forum and it is a waste of time to read redundant questions. Your post will be read, have some patience. Thanks